About this tool
The IEEE-754 Floating-Point Converter shows exactly how a number is stored in memory as a 32-bit single-precision or 64-bit double-precision float, and can reverse a raw bit pattern back into its decimal value. It uses JavaScript typed arrays (Float32Array / DataView) so the bit pattern is the genuine hardware representation, not an approximation.
In forward mode it reports the pattern as hexadecimal and as binary split into its three fields: the sign bit, the exponent (8 bits with bias 127 for float32, 11 bits with bias 1023 for float64), and the mantissa (23 or 52 bits). It also decodes the unbiased exponent and classifies the value as normal, subnormal, zero, infinity or NaN. Crucially it prints the exact stored value read back from the bits — which for float32 often differs from what you typed, making floating-point rounding error visible. For instance 0.1 is not stored exactly in either precision.
In reverse mode you paste a hex pattern (with or without 0x) or a full-width binary string and it reinterprets those bits as a float and shows the resulting decimal value plus the same field breakdown. Everything runs locally in your browser. This is a go-to tool for understanding rounding, comparing single versus double precision, and inspecting the special encodings for ±0, ±∞ and NaN.